1. Field of Invention
The invention relates to a cooling structure of an electric device, and more particularly, to a cooling structure of a plurality of electric devices.
2. Description of Related Art
Coping with recent environmental issues, development of hybrid vehicles using driving force of the motor, fuel cell vehicles, electric vehicles and the like have been increasingly focused. The vehicle of the aforementioned type is generally equipped with a PCU (Power Control Unit) that regulates electric power supplied from the driving battery (at about 300 V, for example) into a desired state so as to be supplied to the motor. The PCU includes such electric devices as an inverter, a filter condenser, and a converter. As those electric devices generate heat upon supply of electricity, they have to be cooled by circulating cooling medium or cooling water therearound.
JP-A-2001-245478 discloses a cooling system of an inverter, which has a high cooling capacity as well as high productivity. The aforementioned cooling system serves to cool the inverter including a high temperature portion in which a unit that generates larger heating value is placed and a low temperature portion in which a unit that generates lower heating value is placed. The cooling system has cooling medium passages for the high temperature portion and the low temperature portion, respectively each of which has a different structure.
As the structure of the cooling medium passage for the high temperature portion of the inverter is different from that for the low temperature portion, the cooling level may be changed depending on the temperature distribution on the inverter. Accordingly, the productivity of the cooling system for the inverter may be improved while keeping the cooling capability.
As the cooling system of the inverter disclosed in the aforementioned publication has cooling medium passages each having different structure for the high temperature portion and the low temperature portion, respectively, the resultant size of the system has to be enlarged.